N(p-n-alkanoyloxybenzylidene(-p&#39;-aminophenyl acetate

ABSTRACT

WHERE X IS AN INTEGER OF 1 TO 10. THE COMPOUNDS ARE PREPARED BY THE REACTION OF PARA-ACETOXYLANILINE AND PARAN-ALKANOLYLOXYBENZALKEHYDE.   1-(N-CXH2X+1-COO-),4-((4-(CH3-COO-)PHENYL)-N=CH-)BENZENE   THIS IS DISCLOSED THE PREPARATION OF NOVEL MESOMORPHIC COMPOUNDS OF THE STRUCTURE:

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3,799,971 N(p-n-ALKANOYLOXYBENZYLlDENE(-p= A UPHENYL ACETATE Edward L. Steiger and Heinz J. Dietrich, Toledo, Ohio, assignors to Owens-Illinois, Hnc. No Drawing. Filed Aug. 23, 1971, her. No. 174,174 Hut. (Ii. C07c 119/10 US. Cl. 260-479 R 2 @lai ABSTRACT F THE DHSCLOSU This is disclosed the preparation of novel mesomorphic compounds of the structure: I

The following equation is representative of the reaction of para-acetoxyaniline and para-n-allcanoyloxybenzalde= The para-acetoxyaniline, also known as para amino if it phenyl acetate, is commercially available. It may be typically used without further purification.

, Schiif bases are prepared by refluxing equimolar quanwhere x is a i t of 1 to The compounds are tities of the p-substituted benzaldehyde and aniline in an= prepared by the reaction of para-acetoxyaniline and parahydrous ethanol for about 4 to 6 hours. The solvent and n-alkanolyloxybenzaldehyde. water are removed and the residue recrystallized several times from ethanol until the transition temperatures remain constant. The crude yields ranged from 70 to 90%. THE DISCLOSURE The infrared spectra show a strong band at 1629 cm.-

This invention relates to the preparation of mesocorresponding to the carbon nitrogen double bond in mofphic compounds M Particularly, this invention Schiff base compounds. Other absorptions are compatible lates to the preparation of mesomorphic compounds with the expected structures. which may be utilized in display type devices. Transition temperatures are determined on a Leitz Mesomorphic materials, typically referred to as liquidorthplux polarizing mlcroscope using Mettler FILZ crystal materials, are organic compounds in a transition heatmg gauge state between crystalline solid and normal isotropic liquid q l i q )-P- mlnophenylacetate forms. Such materials are well known in the prior art. (wlere x 3 Structure) was prepared i Likewise, it is known in the prior art to use Such 1iquid cor ance with th s mvention. The structure was ana yzed at 70.3 percent by weight carbon, 5.81 percent by weight crystal materials 1n display type devices.

In accordance with this invention, there is prepared hydrogen and Pei-Fem by weight nitrogen compared N(p n alkanoyloxybenzylidene) p, aminophenylacetate with calculated theoretical analysls values of 70.78 perliquid crystal compounds of the structure: cent by weight carbon, 6.24 percent by weight hydrogen,

and 4.13 percent by weight nitrogen. The compound 0 0 changed from the crystalline to the smectic phase at g %B about 923 C. and from smectic to isotropic at about 40 135.1 C. p The liquid-crystal compounds prepared in accordance r222 fi g igiig igi gg g preferably 1 to by the with this invention may be utilized in display devices,

especially of the electronic type. 0 Such devices typically comprise a thin. layer of liquid i crystals sandwiched between two sheets of glass. Normally, the thin layer of liquid-crystal material is clear, but when an electric field is applied to it, some and Para-I1"alkanoyloxybenzaldehyde, portions or regions of the material become turbulent so 0 as to scatter light. By controlling the size and shape of H2 it @0130 the turbulent regions, images can be formed. Primarily, this effect is obtained by use of liquid-crystal materials of the nematic type. Where x18 as defined above a Various embodiments of liquid-crystal electro-optical The para-n-alkanoyloxybenzaldehydes i 1118 mventlsn devices are disclosed and illustrated in U.S. Letters are p p y reacting para-hydroxybenzaldehyde with Patents 3,401,252 and 3,410,999; Proceedings of the an pp i n-alkanoic acid halide h both IEEE, vol. 56, No. 12, Dec., 1968, pp. 2146 to 2149; The commercially available) in the presence of an inorganic Gl ss Industry, August 19 PD- 3 to 425; Chemical base such as lithium hydroxide, sodium hydroxide, 01 and Engineering News, Sept, 30, 1968; pp, 32 and 33; potassium hydroxide and water. Organic bases such as Ph i T d J l 1970, 30 t 36; El t i pyridine or trialkyl amines under dry conditions may be July 6, 1970, pp. 64 to 70 US. Letteis Patent 3,322,485 substituted. These reactions are conducted under subto Williams. ambient temper ura a to The p y- It is also contemplated using the liquid-crystal com= benzaldehyde, inorganic base and water or organic base pounds in a charge storage display/memory device, are placed in a reaction vessel. The n-alkanoic acid halide especially multiple gas discharge display/memory panels is then slowly added with external cooling to control a 65 which have an electrical memory and which are capable temperature exothern'r. After addition, the mixture is alof producing a visual display or representation of data lowed, under agitation, to warm to room temperature such as numerals, letters, television display, radar displays, and remain 'for 2 to 4 hours. The reaction mixture is then binary words, etc. quenched into water and the product is isolated by extrac= Multiple gas discharge display and/or memory panels tion witha water immisicible organic solvent, first under of the type with which the present invention is especially basic conditions and then followed by acidic conditions. concerned are characterized by an ionizable gaseous The product is purified by fractional distillation, medjpt- Iu pre of at least two gases at an ap oa In v zen/479a propriate gas pressure, in a thin gas chamber or space between a pair of opposed dielectric charge storage mem= hers which are backed by conductor (electrode) members, the conductor members backing each dielectric member being transversely oriented to define a plurality of discrete discharge volumes and constituting a discharge unit. In some prior art panels the discharge units are additionally defined by surrounding or confining physical structure such as by cells or apertures in perforated, glass plates and the like so as to be physically isolated relative to other units. In either case, with or without the confining physical structure, charges (niec trons, ions) produced upon ionization of the gas of a selected discharge unit, when proper alternating potentials are applied. to selected conductors thereof, are

collected upon the surfaces of the dielectric at specifically defined locations and constitute an electrical field op posing the electrical field which created them so as to terminate the discharge for the remainder of the half cycle and aid in the initiation of a discharge on a sue-- ceeding opposite half cycle of applied voltage, such charges as are stored constituting an electrical memory.

An example of a panel structure containing nonphysically isolated or open discharge units is disclosed in US. Letters Patent 3,499,167 issued to Theodore C. Baker et al.

An example of a panel containing physically isolated units is disclosed in the article by D. L. Bitzer and H. G. Slottow entitled The Plasma Display Panel-A Digitally Addressable Display With Inherent Memory," Proceedings of the Fall Joint Computer Conference, IEEE, San Francisco, Calif., November 1966, pp. 541-647. Also reference is made to US. Letters Patent 3,559,190.

In the operation of the panel, a continuous volume of ionizable gas is confined between a pair of dielectric surfaces backed by conductor arrays forming matrix elements. Typically one or more of the dielectric layers are photoemissive. The cross conductor arrays may be orthogonally related (but any other configuration of conductor arrays may be used) to define a plurality of opposed pairs of charge storage areas on the surfaces of the dielectric bounding or confining the gas. Thus, for a conductor matrix having H rows and C columns the number of elemental discharge volumes will be the product H C and the number of elemental or discrete areas will be twice the number of elemental discharge volumes.

In addition to the matrix configuration, the conductor arrays may be shaped otherwise. Accordingly, while the preferred conductor arrangement is of the crossed grid type as discussed herein, it is likewise apparent that where an infinite variety of two dimensional display patterns are not necessary, as where specific standardized visual shapes (e.g., numerals, letters, words, etc.) are to be formed and image resolution is not critical, the conductors may be shaped accordingly.

The gas is one which produces light (if visual display is an objective) and a copious supply of charges (ions and electrons) during discharge. In an open cell Baker et al. type panel, the gas pressure and the electric field are suflicient to laterally confine charges generated on discharge within elemental or discrete volumes of gas he tween opposed pairs of elemental or discrete dielectric areas within the perimeter of such areas, especially in a panel containing non-isolated units.

As described in the Halter et a1. patent, the space be tween the dielectric surfaces occupied by the gas is as to permit photons generated on riisehzn discrete or elsnte' v ime of gas to p the gas space a surtacs fr the struclt; dielectr. "ins s areas thereby can so as to a other and more remote volumes for discharges at rt uniform applied potentt.

With respect to the memory function of given tliifi charge panel, the allowable distance or spacing between the dielectric surfaces depends, inter alia, on the frequency of the alternating current supply, the distance typicnll," being greater for lower trequencics.

In the practice of this invention, it is contemplated that a particular liquid crystal may be prepared and/or utilized alone or in combination with other liquid-crystal compositions of the same or ditlerent family, e.g. such as mixture of 2 or more compositions. This may be especially desirable since mixtures of compounds may have lower transition temperatures than the individual compounds.

We claim:

1. As a composition of matter, a compound having the chemical structure where x is an integer of 1 to 10.

2. The invention of claim 1 wherein at is 3 and the compound changes from the crystalline to the smcctic phase at about 92.3" C. and from smectic to isotropic at about l35.1 C.

References (lited UNITED STATES PATENTS 3,540,796 11/1970 Goldmacher et al. 260-479 R JAMES A. PATTEN, Primary Examiner US. Cl. XIR. 

